ASI network for explosion-hazard areas

• US 8,242,901 B2
• Filed: 02/22/2008
• Issued: 08/14/2012
• Est. Priority Date: 02/27/2007
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Indefrey, Klaus, Korff, Maximilian, Schiff, Andreas, Wiesgickl, Bernhard
• Primary Examiner(s): Wu, Daniel
• Assistant Examiner(s): SHERWIN, RYAN W
• Application Number:
  US12/071,551
• Publication Number:
  US 20080224850A1
• Time in Patent Office: 1,635 Days
• Field of Search: 340/532, 340/538, 340/500, 340/693.1, 340/310.11, 340/333, 340/425.2, 710100-317
• US Class Current: 340/538
• CPC Class Codes: H02H 9/008 Intrinsically safe circuits

Abstract

At least one embodiment of the invention relates to a fieldbus system, in particular for use in an explosion-hazard area. The fieldbus system, in at least one embodiment, has a plurality of bus line sections with bus lines; an isolating element, by which in each case two of the plurality of bus line sections are coupled to one another and which galvanically isolates the bus lines of the two bus line sections from one another such that this prevents any direct current flowing between the bus lines of the two bus line sections and communication signals are transmitted between the two bus line sections; and a supply source for each of the bus line sections, in order to provide an electrical power supply for field devices which can be connected to the respective bus line section.

Claims

1. A fieldbus system, comprising:

a plurality of bus line sections including bus lines;

a plurality of isolating elements, at least one isolating element coupling two of the plurality of bus line sections to one another, to galvanically isolate the bus lines of the two bus line sections from one another such that a direct current is prevented from flowing between the bus lines of the two bus line sections and such that transmission of communication signals is permitted between the two bus line sections;

at least one supply source for each of the bus line sections, the at least one supply source configured to supply an electrical power supply to field devices connected to a respective bus line section, the plurality of the bus line sections being connected via the isolating elements to form a series circuit; and

a connection section including at least one terminal impedance, and configured to connect at least one bus line section of the plurality of bus line sections to a controller, wherein the connection section is galvanically isolated from the plurality of bus line sections and the connection section is not directly connected to a power supply source and is not directly connected to the field devices, wherein

the at least one supply source is coupled via a decoupling inductance to bus lines of a corresponding bus line section.

2. The fieldbus system as claimed in claim 1, wherein terminating impedances are provided at the ends of the bus lines.

3. The fieldbus system as claimed in claim 1, wherein the at least one isolating element is connected to two bus lines of the two bus line sections, wherein the at least one isolating element includes a transformer with transformer coils and wherein each of the transformer coils is connected in series with a respective isolating capacitance between the two bus lines of the corresponding bus line section.

4. The fieldbus system as claimed in claim 3, wherein a suppressor diode is connected directly in parallel with at least one of the transformer coils of the transformer.

5. The fieldbus system as claimed in claim 1, wherein the supply sources for the bus line sections are designed to be current and voltage limited.

6. The fieldbus system as claimed in claim 1, wherein the plurality of bus line sections are at least partially in an explosion-hazard area, and wherein the at least one supply source for each of bus line sections is outside the explosion-hazard area.

7. The fieldbus system as claimed in claim 1, wherein the at least one bus line section is connected via the connection section to the controller for providing communication with field devices connected to the at least one bus line section.

8. The fieldbus system as claimed in claim 7, wherein a plurality of bus line sections are coupled via a respective isolating element to the connection section.

9. The fieldbus system as claimed in claim 1, wherein the fieldbus system is for use in an explosion-hazard area.

10. The fieldbus system as claimed in claim 2, wherein the at least one isolating element is connected to two bus lines of the two bus line sections, wherein the at least one isolating element includes a transformer with transformer coils and wherein each of the transformer coils is connected in series with a respective isolating capacitance between the two bus lines of the corresponding bus line section.

11. The fieldbus system as claimed in claim 10, wherein a suppressor diode is connected directly in parallel with at least one of the transformer coils of the transformer.

12. The fieldbus system as claimed in claim 2, wherein the supply sources for the bus line sections are designed to be current and voltage limited.

13. The fieldbus system as claimed in claim 2, wherein the plurality of bus line sections are at least partially in an explosion-hazard area, and wherein the at least one supply source for each of the bus line sections is outside the explosion-hazard area.

14. The fieldbus system as claimed in claim 2, wherein the at least one bus line section is connected via the connection section to the controller for providing communication with field devices connected to the at least one bus line section.

15. The fieldbus system as claimed in claim 14, wherein a plurality of bus line sections are coupled via a respective isolating element to the connection section.